I've had to 'rebuild' mine several times since i've got my car. It's not horrible hard, just have to be patience and make sure you THOROUGHLY clean everything. I had a needle in one of my injectors break before while i retorqued the halves together. I never calibrated mine, just wanted it to run so i could drive the damn thing. Haven't had any problems for nearly 10,000 miles now. Couldn't get the halves to seat properly the first couple of times through. I also soaked all the parts in ATF over night just for some reassurance.

"VR no longer stands for VR6, it's now Velociraptor... which is pretty much how a VR6 sounds like."